A STUDY ON THE MARGINAL FIDELITIES AND FRACTURE STRENGTH OF IPS EMPRESS 2(R)CERAMIC CROWNS / 대한치과보철학회지

ABSTRACT

The purpose of this study was to measure the marginal fidelities and the fracture strength of IPS Empress 2. and In-Ceram. ceramic crowns. After constructed of 12 experimental dies for each group, ceramic crowns were fabricated on the metal master dies prepared on the maxillary right premolar. Marginal gaps were measured on the specimen between the margin of each crown and finishing line of the metal master die by using stereo-microscope(SZ-ST. Olympus, Japan) and all specimens were cemented on the metal master die with Bistite II.(Tokuyama soda Co, LTD., Japan) resin cement. Finally, marginal gaps were measured again. To measure of the fracture strength, buccal incline on the functional cusp of specimens were loaded until the catastrophic failure occurred by using the AGS-1000 D.(Shimadzu, Japan). The result of marginal fidelities and fracture strength were statistically analyzed with the SPSS version 8.0 programs. The results of this study were as follows 1. No significant difference was found in the mean marginal fidelities and fracture strength between the IPS Empress 2. and In-Ceram. 2. In comparison of marginal fidelities between before and after cementation, there was significant difference(P<0.05). The IPS Empress 2 system was shown in this study that had good marginal fidelities and fracture strength compared to In-Ceram ceramics. Although this system was acceptable to clinical applications, the system still has to be considered long-term researches about marginal fidelities and fracture strength due to the lack of data about the clinical researches.